<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>条件</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <p v-if="seen">现在你看到我了</p>
    </div>
    <script>
        var app = new Vue({
            el:'#app',
            data:{
                seen: false
            }
        })
    </script>
</body>
</html>